(no subject)
Everyone has heard of holding patterns. They are those little racetracks in the sky that aircraft fly around while waiting for space to clear up so they can proceed with what they want to do, which is nearly always to land. Until quite recently, I hadn't put any thought into exactly how pilots maintained those patterns; if it wasn't just looking outside at the ground, it was probably something high-tech and cool, like a GPS system integrated into a heads-up display that projected little 3d hoops as references for the pilot to fly through. That's how video games handle the problem of having unskilled people not fly into mountains, at least.
As it turns out, it is not like that at all. That would be way too easy. Instead, there is exactly one fixed reference point in the traffic pattern: an arbitrary point in the sky located at the intersection of two bearing lines from radio navigation aids. The rest of the pattern is performed as follows: fly directly at that fix, correcting by guesswork and control feel for the wind. Take a note of precisely how much wind correction, and in which direction, was necessary. Once you've overflown the fix, turn until you're opposite your previous track, then add triple the correction you had on the inbound leg. Fly a minute. Turn again, and repeat. On subsequent laps, vary the length of the outbound leg to try to pin down the inbound leg at one minute long, and vary the angle you fly outbound so the heading you end up flying inbound stays relatively constant.
In other words, far from following a neat racetrack in the sky, my traffic patterns currently look like a plate of spaghetti. Far from some high-tech, intuitive interface, I'm flying along looking at a compass and a stopwatch and using a guess-based heuristic algorithm to correct for unpredictable and variable wind effects. That's fine, I'll learn it, gain skill, and end up not thinking about it anymore.
However--and this is what was bothering me today--this isn't an artificial technique used in the training environment to teach us the basics. This is what real pilots do. When you're 30,000 feet in the sky with 500 other passengers waiting for clearance to land, imagining the pilot cool and competent in the cockpit, he is up there with a stopwatch and a compass, trying to guess what the winds are doing right now.
The safety record of commercial flight gets more impressive to me on a daily basis.
As it turns out, it is not like that at all. That would be way too easy. Instead, there is exactly one fixed reference point in the traffic pattern: an arbitrary point in the sky located at the intersection of two bearing lines from radio navigation aids. The rest of the pattern is performed as follows: fly directly at that fix, correcting by guesswork and control feel for the wind. Take a note of precisely how much wind correction, and in which direction, was necessary. Once you've overflown the fix, turn until you're opposite your previous track, then add triple the correction you had on the inbound leg. Fly a minute. Turn again, and repeat. On subsequent laps, vary the length of the outbound leg to try to pin down the inbound leg at one minute long, and vary the angle you fly outbound so the heading you end up flying inbound stays relatively constant.
In other words, far from following a neat racetrack in the sky, my traffic patterns currently look like a plate of spaghetti. Far from some high-tech, intuitive interface, I'm flying along looking at a compass and a stopwatch and using a guess-based heuristic algorithm to correct for unpredictable and variable wind effects. That's fine, I'll learn it, gain skill, and end up not thinking about it anymore.
However--and this is what was bothering me today--this isn't an artificial technique used in the training environment to teach us the basics. This is what real pilots do. When you're 30,000 feet in the sky with 500 other passengers waiting for clearance to land, imagining the pilot cool and competent in the cockpit, he is up there with a stopwatch and a compass, trying to guess what the winds are doing right now.
The safety record of commercial flight gets more impressive to me on a daily basis.